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2 Sheets-Sheet 1.

(No Model.)

G. W. COY. Telephone Signaling Apparatus. No. 238,360.

Patented March 1, 1881-.

my. I.

George W C0 1 W/x/ gf N. PETERS P110104 n-maRAPHER, WASHINGTUNCD C.

2 Sheets-Sheet 2.

(No Model.)

G. W, OO'Y. Telephone Signaling Apparatus.

Patented March 1,

I'll MW iv I? Iwvenlowm aeorge W C03.

0E lies? out) MPEYERs, PHOTO LITHOGRAFHER. WASHINGTON, D c.

UNTTE STATES GEORGE W. COY, OF MILFORD, CONNECTICUT, ASSIGNOR OF TVVO-THIRDS TO JAMES Gr. SMITH, OF HACKENSACK, NEW JERSEY, AND CHAS. E. BUELL, OF NEW HAVEN, CONNECTICUT.

TELEPHONE SIGNALING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 238,360, dated March 1, 1881.

Application filed September 29, 1880. (No model.)

To all whom it may concern:

Be it known that I, GEORGE W. OoY, a citizen of the United States, residing at Milford,

in the county of New Haven and State of Con necticut, have invented new and useful Improvements in Signaling and Circuit-Changin gApparatus for Telephone-Stations, of which the following is a specification.

The object of this invention is to secure secrecy and prevent interruption of communication between stations in a telephone-circuit, to dispense with the ground-wires heretofore used at stations in effecting secrecy-connections, and to simplify the construction of the station apparatus. The combined call-bells and secrecy-switches which have heretofore been employed have depended largely upon complicated mechanical moving parts, which are subject to wear and liable to become out of order. Myinvention is simplified in its mechanical construction, and depends for its operation upon the action of the electric currents by means which are not liable to become out of order. plishes perfectly the object of debarring stations not in communication from disturbing those which are, by inadvertently calling or from eavesdropping, and by its peculiar construction makes it impossible for the persons using telephones to leave the circuit interrupted by their neglect to properly hang up their telephones.

In the accompanying drawings, Figure 1 is a front elevation of a station apparatus con- 3 5 structed according to my invention, the door of the casing being left open. Fig. 2 is a diagram illustrating the circuits at the station. Fig. 3 is a detached view of the switch-lever, showing its position at the moment of chang- 0 ing circuit from line to telephonic circuit. Fig. 4 is a central longitudinal section of a modified form of electro-magnet.

The letterAindicates a duplex electro-magnet, having separate helices a b coiled upon the same core. The armature C of this magnet is pivoted, at c, in the frame which supports the magnet, and has extending from it a lever, C, which, when attracted by the magnet, strikes the tail d of a bell-hammer lever,

It requires no attention and accom- D, and causes the hammer to strike the bell 5o E, which is mounted upon top of the box or casing F, which incloses the magnet.

G G are adjusting-screws, tapped in metallic posts h h, projecting from the back wall of the box, said screws serving to regulate the throw of lever C.

The letter I designates a metallic lever arranged under the magnet and pivoted to a metallic post, I, projecting from the bottom of the box. This lever is provided with two leaf-springs, 7c and l, projectingobliquely downward from its lower side, and arranged to, at proper times, come in contact with similar springs, m and m, projectin g obliquely upward from the bottom of the box. At one end of this leveris connected a telephone-hook, n, extending downward through an aperture in the bottom of the box, and between the end of the lever and its fulcrum or pivot it.is provided with an insulated downward-projecting stud, 0, which is arranged to strike a bent spring, p, rising from the bottom of the box, and throw said spring out of contact with a metallic bracket, q, also secured to the bottom of the box. A suitable spring causes the lever' to rise when the weight of the telephone is removed from its hook.

The letters L L designate the main line connecting with binding-posts 5 and 6; M M, the telephone-wires connecting with posts 7 and S, and N N the local-battery wires connecting with posts 9 10. From the bindingpost 5 a wire, 1", leads to the metallic post h, and from this post a wire, '1', connects with one terminal of the coil 1), and from the other terminal of the coil a wire, 8, leads to the leaf-spring m on the bottom of the box. From the post 6 a wire, t, leads tothe metallic post l,which supports the metallic lever I. From the post 7 a-wire-, u, loads to the pivot 0 of the armature C, and from said pivot a wire, a, leads to one terminal of the short coil a, and from the other terminal of the coilawire, a leads to the metallic post h. From the post It a wire, a leads to the bracket q, and from the spring p,which is normally in contact with this bracket, a wire, it, leads to post 10. From post 9 a wire, a connects, through wire a with the pivot of the armature. From post 8 a wire, 4;, leads to the upper hinge of the box, and a wire, '0, leads from the hinge to a plate, S, arranged upon the inner surface of the boX- door. From a spring, S, secured to the door and bearing upon the plate a wire, o leads to the lower hinge, and a wire, 0 leads from the hinge to the spring m upon the bottom of the box.

The letter 10 indicates a metallic plate, preferably elastic, secured to the wall of the easing, and lying in the path of themetallic belllever, so as to form a rest or stop for said lever when it falls away from the bell. From this plate w a wire, 20, leads to the spring m, and from the bell-lever or its metal pivot a wire, 10 leads to the post I.

The spring S is arranged to be thrown out of contact with plate S by means of a suitable push-button. (Not shown in the figure.)

When the apparatus is in its normal condition, and the telephone upon its hook, the weight of the telephone depresses thelever I, holding the s 'irings m and 7a in contact with each other, and the springs l and m are separated. The circuit is then, as indicated by the arrows No. 1, Fig.2, from the line to post 5, thence over wire 1" to post h, thence over wire 0" to coil 1), through said coil over wire 8 to spring m, over spring 7, lever I, post I, and wire t to post 6, and thence over the line. When the circuit is thus closed the armature is attracted by the magnet and the lever (J is in contact with screw G, the stud 0 drives spring 19 away from bracket q, thus breakin gthe circuit of the local battery, as will presently appear. Now, when the subscriber desires to communicate with the central office, he takes his telephone off its hook,allowing the lever I to rise, separating the springs m and 7c and bringing the springs Z and m together. At the same time the stud 0 leaves spring 1) and allows it to rise and come in contact with bracket q. The circuit is now from the line, say, to post 5, over wire 1' to post h, and thence, as indicated by arrows N o. 2, Fig. 2, over screw G, lever G, armature 0, wire a, to post 7, through wire M to telephone, thence over wire M, wires 0) and 12, plate S, spring S, wires r and t springs m and l, lever I, post 1, wire 2?, to line. At this time the circuit of thelocal battery is closed from battery to post 9, thence, as indicated by arrows No.3, Fig.2,over wires a" and u to armature-pivot c, thence over wire a to coil a, thence over wire a to post h, thence over wire a to bracket 1, and spring 1) and wire a to post 10, and thence back to battery over wire N. B y operating the push-button to separate spring S from plate S the main circuit may now be broken to sound a bell at the central otfice. An answer having been received from the central office and the subscriber put into communication with another, themain battery is cut out of the line, as usual, at the said central office, and the local circuit of the station alone vitalizes the cores of the magnet through coil a to retain the armature in contact with screw G, this position of the armature being necessary to retain the subscribers telephone in the main circuit.

The operation of the apparatus at all the other stations is as follows: Supposing them to be in normal condition when the main bat tery is taken olt' the line, as soon as the said battery is taken off, the cores of the magnet cease to be vitalized by the coils I), and the armature falls back in contact with screw G. It is now impossible for the subscriber to put his telephone into circuit, for there is no current on the main line to vitalize the magnet through coils b, and the circuit of the local battery is shunted from the coil a, said local circuit being closed as follows: from battery over wire N to post 9, thence over wires a and u to pivot 0, over armature G, lever O, and screw G to post It, (this beinga shorter route than over wire a, coil a, and wire M2,) and from post h, over wire a bracket q, spring 1), wire a to post 10, and back to battery over wire N. Thus the coil (0 cannot be caused to vitalize the cores.

The taking the telephone olf its hook at a station between two others which are in communication, while allowing the lever I to rise and separate the springs m and It, does not break the main-line circuit, but simply causes it to take the route, as indicated by arrows No. 4, Fig. 2, from spring an, over wire 20, plate 10, bell-lever D, and wire 10 to post I, and thence it flows over wire t to the line. The tail of the bell-lever is faced with hard rubber or other insulating material, as shown at 3 in order to insulate it from the armaturelever G.

The springs 71'; and m and l and m should be so bent that when the lever I rises the springs l and on will come in contact with each other before the springs 7c and m become separated; otherwise the main circuit will be momentarily broken and the bell tapped at the central office. This arrangement prevents the bell from being rung by persons taking olf the telephone inadvertently or without intention of callin Instead of the magnet A, having the separate coils a and I), I may use a magnet such as shown in section at A, Fig. 4.

The coil to is continuous, and' its entire length is traversed by the main-line batteryeurrent; but the local battery is to be connected to a loop, b so that its current will traverse only a certain number of the inner layers of the coil indicated .by b and terminatin g at Z). The main line connects with b and I) both, thus traversing the whole coil; or the lever C may be pivoted between its ends and provided with two armatures arranged on opposite sides, a main-line magnet being arranged to attract one, and a magnet in a local circuit to attract the other, both, however, moving the lever in the same direction.

I do not, of course, confine myself to the particular devices and arrangements thereof as now shown and described; but

I claim- 1. In a telephone-station apparatus,the combination, with an automatic circuit-changing device, a main circuit, and a local circuit, of two elcctro-magnets, or their equivalent, arranged to each independently operate an armature controlling said circuit-changing de vice, a switch provided with contacts arranged to connect the main circuit with one of said magnets and disconnect the local circuit from the other magnet by one movement, and by another movement to shunt the main circuit from its connected magnet and connect the local circuit with the other magnet, substantially as described, whereby the said automatic circuit-changing device may be brought under the control of the main and local circuits alternately, for the purpose set forth.

2. In a telephone-station apparatus, the combination, with a circuit-changing device, a main circuit, and a local circuit, of two electrical helices, each provided with a soft-iron core arranged to operate an armature controlling said circuit-changin g device, a switch and contacts, as shown, arranged to connect the main circuit with one of said helices and disconnect the local circuit from the other helix by one movement, and by another movement to shunt the main circuit from its thus-connected helix and connect the local circuit with the other, and a short circuit arranged to be closed by the operation of said armature when released by the magnets, and divert the local circuit from the helix of its magnet, substantially as and for the purpose set forth.

3. In a telephone-station apparatus, the combination, with the main-line connections, helix 7), and armature G, controlling a circuitchanger, the lever I, springs m it and l m, and the connecting-wires r, r, and s, of a suitable auxiliary circuit leading from the spring m around the magnet, and forming an intermediate connection between the main-line connections, substantially as described, whereby when the said helix is disconnected from the main circuit said circuit is maintained.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE W. (JOY.

Witnesses:

JAMES 'l. HIGBY, JOHN W. FOWLER. 

